Nanoscale Solid Freeform Fabrication Process with a Photo-Assisted Spark Plasma Thermal Source

该项目的研究目标是开发一种新的光热纳米制造工艺，通过一层一层的直接写入方式沉积材料来创建纳米级三维结构。该工艺使用激光辅助的火花等离子体在纳米探针尖端和材料表面之间形成，以致密化纳米颗粒。通过调节电能和激光能量，可以控制热能来烧结、巩固和粘合纳米颗粒层。这项研究工作的成果将是：1)证明这种独特的纳米局部激光辅助火花等离子体热源的能力，该热源可通过纳米颗粒烧结自由成形纳米级三维金属特征；2)表征电极上的传热传质及其对纳米颗粒及其附近表面的影响。如果成功，结果将为火花等离子体和热材料工艺以及纳米级制造提供新的思路。该工艺提供的纳米级三维固体自由曲面制造的潜在机会在很大程度上尚未被探索，该工艺代表了非洁净室纳米制造工艺的新范式。这一过程的发展以及对纳米级传输现象的理解将促进实用的3d纳米材料沉积设备的创造，并有望在未来取得更深远的发展。这项研究将被整合到研究者计划现有的和新的课程中，并将采取其他措施来激发本科生和少数民族学生工程师对纳米技术的兴趣。

The research objective of this project is to develop a novel photo-thermal nanomanufacturing process for the creation of nanoscale three-dimensional structures by depositing materials in a direct-write, layer-by-layer fashion. The process uses laser-assisted spark plasmas formed between a nanoprobe tip and a material surface to densify nanoparticles. By adjusting the electrical and laser energies, the thermal energy will be controlled to sinter, consolidate and bond nanoparticle layers to the surface. The outcomes of this research effort will be: 1) demonstration of the capabilities of this unique nano-localized laser-assisted spark plasma heat source for freeform fabrication of nanoscale 3-D metal features by nanoparticle sintering; and 2) characterization of the heat and mass transfer at the electrodes and affects on nanoparticles and nearby surfaces.If successful, the results will shed new light on spark plasmas and thermal materials processes and fabrication at the nanoscale. The potential opportunities for nanoscale 3-D solid freeform fabrication that will be offered by the process are largely unexplored and the process represents a new paradigm for non-clean room nanomanufacturing processes. The development of this process and the understanding of nanoscale transport phenomena associated with it will foster the creation of practical 3-D nanoscale materials deposition equipment, promising even more far-reaching future developments. The research will be integrated into existing and new courses in the investigators program and other steps will be taken to stimulate the interest of undergraduates and minority student engineers in nanotechnology.